Insights into structural features and thermoelectric properties of layered oxychalcogenides, BiCuOCh (Ch = S, Se, Te): promising green materials for energy conversion

ABSTRACT Thermoelectric (TE) technology is considered as one of the promising, eco-friendly, simple and sustainable technologies to generate electricity directly from waste heat and concentrated solar heat. The present TE generators/devices are operating with very low conversion efficiency . Therefore, understanding the electronic and thermal properties of TE materials plays a vital role in enhancing device efficiency. In addition, non-toxic and abundant materials are also important to implement TE technology for large-scale applications. In the past few decades, a lot of research has been done on finding various oxide-based thermoelectric materials. Among many oxide-based materials, oxychalcogenides have received a lot of attention due to their useful thermoelectric properties. This review provides insights into thermoelectrics of selected inorganic oxychalcogenides. A comprehensive discussion has also been made on recent advances in preparation methods and various approaches such as doping, alloying, co-doping techniques adopted for design and optimisation of the TE materials.